Magnum 360

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scott hoffman

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Hi this is scott, I wanted to ask some questions as I know vertualy nothing about the Magnum V8s, I have a 1973 Roadruner that has a LA 360 donner motor in it for quite some time withch has a very slight rod Knock. I pulled the Numbers 340 out for a Stroker build. I have every thing for that motor besides the Push rods and ballencer. Ok the question is I have come across a Magnum 360 rebuilt to stock specks, 30 over, car pan, Eddy manifold and carb, 360 pullies, and a rebuilt 904 trans, for $1400. The 340 would be grate to have backi in but the plug and play of the magnum is a nice option? What is the going rate for a rebuilt magnum? can I use my 727 trans, will the B&M falf moon flex plate work on the Magnum? I have alot to learn. Thanks Scott
 
Depends on what heads the Mag has on it and what flywheel it has now.
Since the Mag has a matching 904 with it then either it has a Mag balanced flex plate already, or an balanced converter.
If it has the balanced flex plate then you can slap your 727 right on it (as long as the bolt holes for the converter are the same, and there are no weights on the converter.

If it has stock Magnum heads you will want to change those for something that isn't or doesn't crack, like EQ's and if you do that you will want to swap the cam, springs, retainers and clips for something capable of using the new cam.

You would be ahead by talking to our member magnummopar as he does this for a living and can give you some good details.
If the Mag was rebuilt by someone reputable with proof and already has aftermarket heads on it 1,400 is a total steal even without the trans.
 
TrailBeast said:
Depends on what heads the Mag has on it and what flywheel it has now.
Since the Mag has a matching 904 with it then either it has a Mag balanced flex plate already, or an balanced converter.
If it has the balanced flex plate then you can slap your 727 right on it (as long as the bolt holes for the converter are the same, and there are no weights on the converter.

If it has stock Magnum heads you will want to change those for something that isn't or doesn't crack, like EQ's and if you do that you will want to swap the cam, springs, retainers and clips for something capable of using the new cam.

You would be ahead by talking to our member magnummopar as he does this for a living and can give you some good details.
If the Mag was rebuilt by someone reputable with proof and already has aftermarket heads on it 1,400 is a total steal even without the trans.
Click to expand...


Thanks I need to ask about the heard as I did not know the stockers were prawn to cracking.
 
TrailBeast said:
Depends on what heads the Mag has on it and what flywheel it has now.
Since the Mag has a matching 904 with it then either it has a Mag balanced flex plate already, or an balanced converter.
If it has the balanced flex plate then you can slap your 727 right on it (as long as the bolt holes for the converter are the same, and there are no weights on the converter.

If it has stock Magnum heads you will want to change those for something that isn't or doesn't crack, like EQ's and if you do that you will want to swap the cam, springs, retainers and clips for something capable of using the new cam.

You would be ahead by talking to our member magnummopar as he does this for a living and can give you some good details.
If the Mag was rebuilt by someone reputable with proof and already has aftermarket heads on it 1,400 is a total steal even without the trans.
Click to expand...

i talk to the guy and he was telling me that he recalls the guy he got the motor from saying it has the EQ heads on it, but I was wondering if there is a way to tell by looking at the heads to tell if they are the EQ heads?
 
scott hoffman said:
i talk to the guy and he was telling me that he recalls the guy he got the motor from saying it has the EQ heads on it, but I was wondering if there is a way to tell by looking at the heads to tell if they are the EQ heads?
Click to expand...

EQ's are marked on the end.
The 318B number is for LA pattern drilled intake instead of Magnum.

EQ.jpg
 
Im going to try to get a look at it this sunday, the guy says for 1500 I can get the Mag, witch i hope has the EQ heads on it, the 904, with the weighted Flex plate, new converter, new ED carb, and some upgraded electronic distributer kit he has to go with it.
 
I just got a set of eq heads none la yalked to jegs and they said my stock valve springs and all would work for for an aftermarket camshaft due to eq designing the heads or machining them is this true I am doing this build on a very small budget and if I can put that money elsewhere
 
scott hoffman said:
Thanks I need to ask about the heard as I did not know the stockers were prawn to cracking.
Click to expand...
Yes, the factory heads are known to crack. However, rarely does the cracks ever cause a problem. There are so many of these magnums with 250,000 ++++ miles and still run excellent, and most probably have cracked heads. Of course, EQ would be better as they are less likely to crack, have a little better flow than factory, and would come with a better spring.
 
318willrun said:
Yes, the factory heads are known to crack. However, rarely does the cracks ever cause a problem. There are so many of these magnums with 250,000 ++++ miles and still run excellent, and most probably have cracked heads. Of course, EQ would be better as they are less likely to crack, have a little better ,,, Mine are bare. Im pretty sure he said that the assembled ones are oem and that if I put my stock ones on it they would work for a .501/.513 lift camshaft. Is this true ?
Click to expand...
 
Well idk what happened with my reply but I need to lnow if I put stock springs on my EQs can I put a camshaft with .501/513 lift
 
chris100 said:
Well idk what happened with my reply but I need to lnow if I put stock springs on my EQs can I put a camshaft with .501/513 lift
Click to expand...

For that lift it would be highly recommended to get at least the retainer and lock set from moparmagnum.com or Hughes.
I replaced the springs with a Hughes 310lb open set which I really didn't have to but I felt a lot better about it. (200 bucks or so for the springs and retainers, locks)
The retainers are designed to allow more spring bind and lift clearances because the stock EQ's and valves are only really safe to run just a bit over the stock cams without the extra clearance the retainers give (they sit a bit higher on the valve stem)
My cam is pretty much exactly the same lift as yours, and the retainers and locks were a must to make sure the retainers didn't run into the stem seals, and the springs highly recommended.

Keep in mind the springs have to pull those valves closed at higher RPM's and think about what happens if they don't.
 
Hot rod has an article where they took a used magnum.....added cam heads intake and carb and got like 438 hp.....
 
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